Pneumatic pump



n. II. REEVES.

PNEUMATIC PUMP.

APPLICATION FILED IUNE2I,'I9I9.

1,385,752. Patented July 26,/ 1921.

3 SHEETS-SHEET1.

lllIh', IIIIIIII l.)

v INVENTOR D. H. REEVES.

PNEUMATIC PUMP.

APPLcATloN immuun-:21, 1919.

1,385,752. Patented July 26, 1921.

3 SHEETS-SHEET 2.

D. H. REEVES.

PNEUMATIC PUMP;

APPLICATION FILED IuIIE 21, I9Is.

PATENT OFFICE.

DONALD I-I. REEVES, OF DAYTON, OHIO.

PNEUMATIC PUMP.

Specification of Letters Patent. Patented July 26., 1921 Application filed June 21, 1919. Serial No. 305,720.

T 0 all whom it' may concern Be it known that I, DoNALD H. REEVES, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Pneumatic Pumps, of which the following is a speciication.

This invention relates to a pneumatically operated pump particularly designed for use on an airplane, to pump gasolene from they main tank to the gravity tank, or to the carbureter, or other desired point.

It is desirable, in aeronautic work, to use compressed air for elevating gasolene to the gravity tank or to the carbureters; the pump of this invention utilizes compressed air as the operating means, and yet does not subject the main gasolene tank to air pressure. Obviously, if the main tank is at a pressure greater than the atmospheric pressure, in order to cause proper How of gasolene, the system becomes inoperative in case a bullet should puncture the tank, or should it spring a leak. Y

The pump of my invention comprises two pressure chambers. In each chamber there is a bellows and the bellows are connected by a pipe, so that as one bellows expands, the other contracts, the interiors of the two bellows being filled with a substantially incompressible fluid, such as glycerin. The use of the bellows avoids the use of reciprocating parts. The use of reciprocating parts, in gasolene pumps has been found unsatisfactory on account of the diniculty in properly packing the piston and piston rod to prevent leakage of gasolene.

My invention further comprises means for allowing the chambers to fill with gasolene, and means for alternately subjecting the two chambers to air pressure, so that either one chamber or the other is always delivering gasolene.

My invention further comprises means for alternately venting each chamber, that is to say, means for allowing the air that lills the chamber after it has delivered its quota of gasolene, to escape to the top of the main gasolene tank.` where it relieves the suction there, and allows lasolene to fill the chamber that is being vented.

My invention further comprises means for controlling the rate oi" flow of the liquid, such as glycerin, contained in the two bellows, from one bellows to the other,

chambers of the an adjustment which controls the rate of Y pumping of the pump.

Other objects and advantages will appear as the description proceeds.

In the drawings, illustrating one embodiment of my invention, Figure .l is a sec tional view taken on a line passing through the valve chamber of the pump.

Fig. 2 is an inverted section of the pump, taken on the line 2 2 of Fig. l, and looking 'in a direction of the arrows.

F ig. 3 is a plan view of the pump.

Fig. 4, shows a section of the pump taken on the line 4 4 of Fig. 8.

Figs. 5, 6 and 7 are sections taken on the lines 5 5, 6 6 and 7 7, respectively, of Fig. 3.

F ig. 8, is a view showing the valve mechanism of Fig. l in another position.

Fig. 9 is a section on the line 9 9 of Fig. 4.

Referring now to Figs. 1 and 2, the two pump are formed by a b ottom wall 1, side walls 2, and a partition 3, which divides the space into two chambers, one of which I will call the valve chamber, indicated by'V, and the other which I will call the auxiliary chamber, indicated by A.

A cover C, when placed in position as shown in Fig. l completes the two said chambers. The side walls 2 and cover C may be provided'with appropriate lugs 4, suitably drilled for bolts 5 to secure the cover in position.

A gasolene inlet pipe k6, preferably cast integrally with the cover C, is threaded as indicated at 7, for the attachment of a con nection, not shown, leading to the bottom of the main gasolene tank, not shown. This pipe 6 is provided with a downwardly extending branch 8, which merges into two branches 9, controlled by 4one way check valves l0, to deliver gasolene into the auxiliary chamber A. The pipe 6 also delivers gasolene to a precisely similar delivery pipe 8 provided with branches 9 and check valves l0 to deliver gasolene to the valve chamber V.

The cover O is also provided with a gasolene outflow pipe 1l. which is threaded as at 12 Afor the attachment of a pipe leading to the gravity tank or the carbureters, not shown. Suitably mounted in the cover C is a delivery pipe 13, which extends nearly to the bottom of the valve chamber V, and

whichA at its upper end opens into the outflow pipe 11,v this opening being controlled by the one-way upwardly opening check valve 14. A precisely similar pipe 13', provided with a check valve opens into the auX iliary chamber A and into pipe 11.

Cover C is further, provided with a passage 15, which is in free communication with the auxiliary chamber A, at one end and whichis in communication with the valve chamber V under certain conditions to be described. Y

. A recess 16 is cut in the bottom part of the cover C. 1n this recess is mounted the valve block 17. This block 17 is provided with a recess 18 for Ian air valve, which recess is narrowed at its upper and lower parts to form beveled valve seats. The, upper'part of the recess 13 is in communication with a hole 19 in the cover C which in turnis in communication with the passage 15. `The valve block 17 is also provided with ya recess 20, which is `Haring vat its upper and lower parts"` to form beveled seats. TheV upper part of the recess 20 is in communication with the passage 21, which in turn is in communication with the passage 15. The lower part of the recess 2O vis open tothe interior of the valve chamber V.

Mounted to move in the recess 1,8 is an air inlet valve 22, which when in its uppermost position as sho kvn in Fig. 4 closes passage 13y to communication withthe passage 15 and leaves it in communication with the valve chamber V. Valve- 22 is provided with a guide 23Vmoving in, the aperture 19'and is carried by a valve stem 24, provided with lugs 25 and 26. The lower end of the valve stemv 24 is loosely mounted in the fixed guide 27. Y y Y Y Mounted to move in the recess 2O is a vent valve 28, provided with valve faces 29` and 30, which when the valve is in its uppermost position as shown in Fig. 4 puts the passage 2O in communication vwith the passage 15 and closes the passage 2O to communication with the valve chamber V. Valve 23 is provided with a valve stem 24', lugs 25 and '26', and has its lower end mounted to move loosely in a fixed guide 27.

Referring now to Fig. 9, the valve block 17 is provided with a hole 31which at one endV communicatesV with the valve passage 18 andv at its other end'opens into the vertical air inlet passage 32. This air inlet passage 32 communicates with an opening 33. which in turn registers with the air inlet pipe 34,

.to whichis connected a lsupply of compressed air `from any suitableI source. This air pipe 34 Vmay be provided with a downwardly opening check valve 35.

The recess '20for the vent valve is in communicatio-n with a passage 36, horizontally drilled as shown in Figs. 1 and 3. Passage 36 at its other end is in communication with the vertical passage 37, which opens into the vent passage 38, in the cover C. A vent pipe 39 may be inserted in this opening 38 and at its other end, not shown, it opens into the top of the gasolene tank. Y

The guide 27 may be formed integrally with a substantially U-shaped element 40, which is secured to the under side ot' the cover C by the screw 41. The guide 27 may be formed integrally with an element 40 precisely similar to the already described element 40. The two elements 40 and 40 are mounted in parallel relationship, spaced apartslightly so as'to define a slot between them.

Pivot-ally mounted in this slot is a latch 42 onv the pivot 43 carried by the two elements 40. The latch 42 is provided Vwith upper and lower lugs 44 and 45, (see Figs. 1 and 8) which vare adapted to operate with a yoke 46, that engages with the valve stems 24 and 24', Iand which! is positioned between lugs 25 and 26 and 25 and 26', respectively, so that the yoke will move vwith both valve stems. Y

The latch 42 is provided with an extension 46 which at its lower end carries a transversely extending rod47. Another rod 48 is carried by the two elements 40. A pair of springs 49, 49 have their lower ends engaging with the rod 47 and their upperl ends engaging with the rod 48.

The'latch 42 is provided with arearwardly extending lug 42', the purpose -of which will appear later.

Suitably attached to theV under side of the cover C at their upper ends are two bellows,

S 'and S', one positioned in the valve cham-` ber V and the other inauXiliary chamber A.

' Each bellows isl-p'rovided with avbase plate 50,v which in turn carries guiding elements 51 and 52, coperating with a guide tube 53` carried by the cover C,'all lot which coperate to effect smooth movement of thebellows. The cover C is provided with a pipe 54 preff erably integral therewith which pipethrough downwardly extending` passages 55' and 56 is in communication with the interiors of the two bellows S and S. Interpolated at a suitable point in the pipe 54 is a. needle valve 55. The interiors ofthe two bellows, aswell as the pipes 54. 55 and 56 are filled with some suchliquid as glycerin, a cap 5S may be threaded on to the cover C over the 4needle valve to prevent leakage. The needle valve may Ialso carry a lock nut 59. y p The bellows S has attached thereto the bent plate 60. the upwardlyfextending arm 61 of which is provided with a slot 62 in which slot engages the already describedflug 42' of the latchi42.

V The operation of the device will now be described. With the parts positioned Ias shown in Fig. 4, chamber V is presumed to be full of gasolene that has tlowedin through and 31.

the inlets 9', by gravity and the chamber A is shown as venting. It will be noted from the position of the air valve 22 that the valve chamber V is being subjected to the yair pressure from the compressed air pipe 34, it being led thereto through the passages 33, This air pressure forces the gasolcne contained in the chamber V upwardly through the delivery pipe 13 and into the outlet pipe ll. Valve 28 during this operation is closed with respect to the chamber V so that it is not in communication with the vent.

At the same time the air, in chamber A is escaping therefrom through the pipe l5 into the valve passage 20, passage 36, passage- 37 and thence into the vent pipe 39, to the top of the gasolene tank. This relieves the air pressure in the chamber A and allows gasolene to flow into that chamber through the passages 9. While either chamber is subject to air pressure the check valves l0 or l0 will of course be closed to prevent entry of air into the pipes 8 or 8.

The air pressure inthe chamber V slowly compresses the bellows S and forces the glycerin contained therein through the pipe 54 into the other bellows S, thereby causing it to expand.

As the bellows S moves upwardly as de-V scribed, it carries therewith the arm 6l, (see Fig. 8), which gradually lifts the lug' 42 of the latch 42, and so causes the latch 42 to turn about the pivot 43. During this operation it will be apparent that the rod 47 to which is attached the lower ends of the two springs as already described will move to the right so that the spring will tend to assume a position to the right of the pivot 43. As soon as the spring passes this pivot 43 it will lift the lower end 46 of the latch 42 which in turn will depress the lug 44 of the latch 42 causing it to engage with the yoke 46 and force it downwardly, it, in turn, moving both-the valve stems 24 and 24 downwardly to reverse the position of the two valves 22 and 28. This new position of the parts is shown in Fig. 8. In that position it will be understood that the air valve 22 is in its lowermost position thereby letting in air pressure into the pipe l5 and subjecting the chamber A to air pressure.

At the same time the vent valve 28 is in its lowermost position and opens the Vchamber V to the vent.

Chamber V will now iill with gasolene and the air contained therein will escape through the vent. Chamber A, being subjected to air pressure will force gasolene out through the delivery pipe 13 into the outlet pipe 11, the check valve 14 lifting to allow this outflow. The bellows S is now expanded and the bellows S contracted. The air pressure now on the chamber A forces the bellows S to contract again which causes a iiow of glycerin back into the bellows S and an .expansion of the same. As bellows S expands the upper edge of the slot 62 will bear against the lug 42 and carry it downwardly to cause the projection 46 to move to the. left, as shown in Fig. l until the springs 49 pass by t-he pivot 43, whereupon the springs will cause the latch 42 to move back into the position shown in Fig. l to reverse the positions of the valves 22 and 28 and startthe cycle of operations just described over again. It will be apparent that the rate of operation of the pump is dependent upon the rate of the contraction. and expansion of the bellows, and the latter in turn is dependent upon the rate of flow of the glycerin from one bellows to the other. By providing the needle valve 55 to control the How of glycerin it will be apparent that the rate of operation of the bellows, and consequently the speed of the pump, can be regulated. In place of glycerin any suitable liquid could of course be used.

While I have illustrated a particular embodiment of my invention it should be understood that it could be carried out in other ways, as defined in the Jfollowing claims.

' I claim as my invention l. Ina pneumatic pump, two pump chambers, a compressed air supply, a vent for said chambers, a compressed air inlet valve controlling both chambers, a vent valve common to both chambers, and intercommunieating bellows in said chambers operable by the compressed air and adapted to actuate both of said valves, the movement of said valves by the bellows being independent of the pumping action.

2. In a pneumatic pump, two pump chambers, a compressed air supply, air inlet valve arranged to admit air under pressure to said chambers, a vent valve common to both chambers, and bellows in said chambers having operative connection with said valves to simultaneously shift them to admit compressed air to one chamber and at the same time vent the other chamber, the movement of said valves by the bellows being independent of the pumping action.

3. In a pneumatic pump, two pump chambers, a compressed air supply, air inlet valve arranged to admit air under pressure to said chambers, a vent valve common to both chambers, bellows in said chambers having operative connection with said valves to simultaneously shift them to admit compressed air to one chamber and at the same time vent the other chamber, the movement of said valves by the bellows being inde pendent of the pumping action, and a fluid pressure transmission passage placing said bellows in communication with each other.

4. In a pneumatic pump, two pump chambers, a compressed air supply, an air inlet valve arranged to admit air under pressure to said chambers, a vent valve common to both chambers, bellows in said chambers having operative connection with said valves to simultaneously shift them to admit compressed air to one chamber and at the same time vent the other chamber, the movement of said valves by the bellows being independentof the pumping actiom a iuid pressure transmission passage placing said bellows-in communication with each other, and means for Varying the capacity of said passage to regulate the speed of flow of the fluid therethrough.

5. In a pneumatic pump, two pump chambers, a compressed an' supply, valve means toadmit compressed air to one chamber and simultaneously vent the otherchamber, and actuating means for saidvalve means em-v bodying bellows in said chambers having connection with said valve means, the moveA ment of Vsaid valve means by the bellows bcing independent of the pumping action, said bellows being in open pressure communication/With each other.

6. In a pneumatic pump, two pump chambers, 4a compressed air supply, valve means controlling the admission of compressed air to and the venting oi said chambers, 4and interdependent luid pressure connected bellows in said chambers having operative con nection with said valve means, the movement of said valve means by the bellows being' independent` of the pumping action.

In testimony whereof I afIiX my signature.

DONALD H. REEVES. 

